Spore Plants and Rhyniophytes

• Higher plants are mainly autotrophic
• They have a system of conductive and covering tissues
• The body is a cormus, divided into vegetative and generative organs

Spore Plants

• Arose about 420 million years ago in the Silurian period from green algae
• Algae thalli were dichotomously branched
• The transition to dry land was associated with anatomical specialization and morphological differentiation of the original thallus into organs
• Spore plants are divided into the following divisions: Ryniorasty (Rhyniophyta), Machorasty (Bryophyta), Plavúňorasty (Lycopodiophyta), Prasličkorasty (Equisetophyta), and Sladičorasty (Polypodiophyta)

Division: Rhyniophytes

• These are fossil plants that grew in the Silurian and Devonian periods in shallow waters or marshy soil
• They became extinct at the end of the Devonian period
• These plants represent the transition of plants from an aquatic environment to dry land
• The only organ was the stem, which also fulfilled the function of the root; it was green, providing a nourishing function
• The above-ground stem was dichotomously branched, and the terminal, dichotomous branches were called telomes, which were connected by unbranched mesomes
• Some telomes were terminated by spores, called fertile telomes; others were without spores and had an assimilative function, called sterile telomes
• The middle of the stem was traversed by a woody-centered vascular bundle
• Plants with spores represented the asexual generation of the sporophyte
• From the spores, new plants grew, which had fertile telomes terminated by male (stamens) and female (carpels) reproductive organs
• These plants form the sexual generation of the gametophyte
• The fusion of the male and female gametes produced a diploid zygote, from which another asexual generation sprouted
• For riniophytes, there is an equal-shaped (isomorphic) alteration of generations
• Genera Psilophyton and Rhynia (e.g., Rhynia major)

Division: Mosses

• Their body consists of a thallus, as in lower plants
• They are multicellular, green, and spore-laden thallus plants
• The oldest types of mosses have a body formed of a scaly thallus
• Other mosses have a thallus divided into roots, stems, and palisades, which already have differentiated integumentary tissue on the surface
• The roots perform the function of roots
• In the stem, some mosses have conductive tissue
• In the leaves, the tissue is differentiated into assimilative and conductive
• The alternation of generations is prominent in them
• Only plants where the gametophyte has prevalence
• From a single-celled haploid spore, a green protocorm sprouts in a suitable environment
• Green moss plants develop on it from buds, which are monoecious or dioecious
• Monoecious plants have both types of reproductive organs on one plant
• Dioecious plants have male reproductive organs on male moss plants and female reproductive organs on female plants
• In the stamen, male reproductive cells are formed (spermatozoa)
• In the carpels, a non-motile female reproductive cell is formed, an egg cell
• Fertilization takes place in an aquatic environment where the spermatozoa move to the carpels
• The fusion of cells forms a zygote from which a diploid cylindrical stalk with spores develops
• Within the spore capsule, meiosis occurs, resulting in haploid spores
• The alternation of generations is homosporous and heteromorphic
• The predominant part of the life of mosses is the green gametophyte, the sporophyte is dependent on it and fused with the gametophyte

Importance

• They absorb large amounts of water and protect the soil from drying out
• They keep the soil moist for the trees and loose on the surface

System

• Class: Liverworts (Hepaticopsida)
• Porcupine multi-form - scaly thallus, cosmopolitan species occurring in wet places, class: Mosses (Muscopsida)
• Curly mermaids, Bievian plonks, Gray whiting
• Peat bogs are plants that die off at the base, still growing at the top
• Over the centuries, they have formed thick layers of peat

Division: Plavúnorasty

• In the Paleocene, they were trees of arborescent growth
• Today, they are herbs of smaller size
• The body is differentiated into root, stem, and leaves
• The stem is creeping and dichotomously branched
• There are two types of leaves: green, trophophyllous with assimilation function, and leaves bearing spores = sporophylls, are often grouped into spikes at the top of the stem
• At the base of the upper side of the leaf is a kidney-shaped spore, in which spores are formed, which may be morphologically identical isosporous or morphologically different heterosporous
• Heteromorphic alternation of generations is typical for them
• The gametophyte is more reduced, which is related to the transition of plants to dry land; the sporophyte predominates
• The gametophyte is only a small protophyte bearing stamen or carpel
• Common plavun, clavate plavun - protected in our country

Division: Horsetails

• In the Paleocene, they had an arborescent growth (20-30 m, up to 1m thick)
• The fossilized bodies form today's layers of hard coal
• Today, they are perennial herbs
• The stem grows out of the ground; it is hollow, segmented, whorled branched, and grooved on the surface
• The cell wall is permeated with SiO2
• The leaves are simple, scaly, non-green, arranged in whorls and fused at the bases into sheaths
• Spores are spherical, green, with 4 ribbon-like spreaders at the end, called hapters
• Green petiolar primordia grow from the spores, either unisexual or bisexual
• Heteromorphic alternation of generations is typical for horsetails Field horsetail (Equisetum arvense) - forms 2 morphologically and functionally distinct stems
• A non-green, 20 cm brown shaft grows out of the ground, which has over-wintered in the spring, which is not capable of photosynthesis
• It is fed from the ground and terminated by a cluster of sporous leaves
• It has a reproductive function and is therefore referred to as a spring stem, a fertile stem
• After the spores burst, the spores are released and dispersed by wind in large groups from the mother plant
• After the spores are released, the spring shaft dies and a green summer shaft grows out of the same ground, sometimes referred to as a sterile shaft
• It has a nourishing function
• Forest horsetail - the spore spike forms at the end of a green shoot
• Marsh horsetail

Division: Sweetroots

• They reached their peak in the Mesozoic, reaching shrubby growth
• Today's species are mostly herbs, less often woody
• They grow in shady places
• Leaves - provide nutrition and spore formation and are referred to as trophosporophylls
• They are large, growing directly from the ground or above-ground stems
• They are 2x-3x pinnately compound
• On the underside are sporangia arranged in heaps and protected by an awning = ostera
• They have a heteromorphic alternation of generations; compared to mosses, the sporophyte is much more perfect and adapted to life and reproduction in a terrestrial environment
• Under favorable conditions, the spore germinates into a thin green filament, which later expands into an area
• A heart-shaped protophyte with a number of anchoring filaments is formed
• Among them are stamen and carpel
• The protophyte is small, about 0.5 cm
• At least a drop of water is needed for fertilization so that spermatozoa can move to the carpel with the egg cell
• After fertilization, a new plant grows from the zygote
• Common male fern, common tapeworm, ostrich feather fern, common licorice, red scolex
• Common eagle fern, Marsilea quadrifolia